The present disclosure relates to a display unit including, for example, a self-luminous device such as an organic EL (electroluminescence) device and a method of manufacturing the same, an electronic apparatus, and an illumination unit. Moreover, the present disclosure relates to a light-emitting device using wavelength-converted excitation light and a method of manufacturing the same.
High-performance display devices are desired along with acceleration of development of information and communication industry. For example, organic EL (electroluminescence) devices are self-luminous type display devices, and are superior in viewing angle width, contrast, and response speed (for example, refer to Japanese Unexamined Patent Application Publication No. 2008-53229). Such self-luminous type devices are individually separated by a separation film made of an insulating material.
In recent years, displays using organic EL devices as light-emitting devices for wide color gamut flat panel displays are attracting attention.
Typical methods of colorizing organic EL devices include a method of arranging, on a plane, light-emitting layers emitting three primary colors, i.e., red, green, and blue, and a method of dividing light into three primary colors through arranging, on a plane, color filters above a light-emitting layer emitting white. In the former method, typically, the light-emitting layers are formed by vacuum deposition; however, to arrange light-emitting layers of three primary colors on the plane, it is necessary to separately form the light-emitting layers of three primary colors with use of a metal mask. Accordingly, there is an issue that it is difficult to reduce a pixel size and to increase a pixel area. In the latter method, since it is not necessary to separately form the light-emitting layers, a reduction in pixel size and an increase in pixel area are easily achieved. However, emission spectra of three primary colors are determined by optical spectra of color filters. Color filters using a typical dye have a broad transmission wavelength, and cause not some little absorption in a maximum transmission wavelength region. Therefore, there are issues that a reproduced color gamut declines, and that luminance declines due to loss of emitted light.
On the other hand, for example, Japanese Unexamined Patent Application Publication No. H3-152897 discloses a method of obtaining three primary colors through using a combination of a light-emitting layer emitting blue light or ultraviolet light used as an excitation light source and a wavelength conversion layer using a fluorescent material or the like. In this method, only a light-emitting layer of a single color is necessary, and it is not necessary to separately form light-emitting layers of three primary colors; therefore, a reduction in pixel size and an increase in pixel area are achievable. Moreover, since any fluorescent material is freely selected as the material of the wavelength conversion layer, design of an optimum color reproduction range and an improvement in light emission efficiency are achievable. However, there is an issue that, in the case where it is difficult for the wavelength conversion layer to sufficiently absorb excitation light, the excitation light passes through the wavelength conversion layer to be mixed with light whose wavelength is converted into a fluorescence wavelength by the wavelength conversion layer, thereby causing a decline in color purity.
To solve this issue, for example, Japanese Unexamined Patent Application Publication No. 2008-41361 discloses a color-light-emitting device having a configuration using a color filter which allows fluorescent light to pass therethrough and block light other than the fluorescent light. Moreover, Japanese Unexamined Patent Application Publication No. 2011-76769 discloses an organic EL device having a configuration adapting a technique of producing optical resonance through adjusting positions of a light-emitting layer and a reflection layer, depending on an emission wavelength.